The invention relates to a system and method for handling moist bulk granular material and in particular to a system and method for handling and transporting moist animal feed.
It has been known in the feeding industry that it is desirable to provide cereal grain by-products, including moist corn gluten meal and/or corn gluten feed, to animals such as cattle to rapidly increase their weight and bring them to market early. Grain by-products are generally defined and described by the Association of American Feed Control Officials, Incorporated (2001, at page 243) and include, for example corn gluten feed. In the past it has been possible to supply moist grain by-products to animals if the animals were located in the vicinity of a corn processing plant. The moist grain by-products could be shipped by truck. This mode of transportation, however, is inefficient and costly, particularly if bulk quantities of moist grain by-products were being shipped over long distances. In addition, the likelihood that the shipment of moist grain by-products ending up being contaminated at the point of delivery increases significantly when shipped over long distances, such as thousands of miles. This is because the moisture in the product allows for the growth of microorganisms such as bacteria, fungi, yeast, and the like.
In the past in order to solve this problem, grain by-products have been dried and generally pelletized before shipping. The dried, pelletized product has an increased shelf life and the shipping costs are considerably reduced because water is not being shipped with the product. However, drying the product causes a significant decrease in nutritional value of the grain by-product feed to animals. This would be desirable to avoid. Hence, it would be desirable to ship a product that is not dried to ensure that the animals are fed a product that is high in nutritional value.
Investigations have been made as to whether conventional rail systems could be used to ship moist grain by-products. Unfortunately, most rail cars such as a hopper or coal car are designed in such a way that an unloading orifice or chute has a reduced cross-section. This reduced cross-section would tend to restrict the flow of moist material, such as the instant moist grain by-products, out of the car. With moist grain by-products, it would be almost impossible to empty such a car having a restricted chute. The moist product would stick and clog the orifice or chute. If a coal car was used to haul moist grain by-products, and dumped using a standard coal-type receptacle, this also would contemplate a very deep hole with very narrow cone-like receptacles used to receive coal. These systems would not work, if at all, with moist grain by-products.
Further, the high moisture content of the moist grain by-products (which generally is from about 30 to about 70 percent weight), together with a relatively acid pH of the meal, would cause an uncoated or unlined steel car coal car to corrode. This corrosion would cause the moist product to stick onto the rough corroded interior surface of the car, as well as potentially contaminate the grain by-product.
What is needed then is a system for shipping and handling a moist perishable product, such as moist grain by-products over long distance while maintaining the product in substantially stable uncontaminated condition to maintain its nutritional value.